This proposal has three major purposes: First, to determine the site of action and afferent pathway for the satiety action of exogenous bombesin administered perpherally in the rat; Seconds, to test the hypothesis that the satiating effect of food in the stomach is mediated, at least in part, by bombesin released from the stomach in the rat; Third, to analyze the neural and/or endocrine mechanisms of the satiety effect of lateral hypothalamic injections of bombesin in the rat. The theme is to continue the analysis of the role of preabsorptive mechanisms (especially peptide functions) in the elicitation of postprandial satiety. The central goal is to determine the peripheral mechanisms controlling meal size. This knowledge should present opportunities to develop physiologically-based treatments for obesity and for bulimia.